| 摘要 |
PURPOSE:To remove a small amount of organic contaminant deposited on the surface, by rotating a wafer which is being immersed in a washing liquid while feeding ultrasonic vibration, by supplying O2 into the washing liquid, and by irradiating the wafer with ultraviolet rays through the washing liquid. CONSTITUTION:A diluted liquid of persulfuric acid is supplied through a tube 2d and O2 bubbles with high purity are supplied through a tube 6, while a wafer A is irradiated with ultraviolet rays from lamps 9 through the persulfuric acid liquid. Moreover, ultrasonic vibration is applied to the wafer W from a vibrator 10 while the wafer W is rotated by a belt 13. In this structure, organic contaminant deposited on the wafer surface is activated by the ultraviolet rays, and may be removed perfectly by a multiplier effect of physical washing action utilizing the ultrasonic vibration and chemical washing action resulting from nascent state O which is produced by chemical reaction of O2 irradiated by the ultraviolet rays and active sulfuric acid radicals which are produced by chemical reaction of persulfuric acid irradiated by the ultraviolet rays. At this time, rotation of the wafer W uniforms washing of the surface. |
